Field of the Invention
The present invention relates to a method for repairing a honeycomb core sandwich structural body, and a repaired product obtained by repairing the honeycomb core sandwich structural body.
Description of the Related Art
A lightweight and highly-rigid honeycomb core sandwich panel is used as an outer panel (skin) forming an outer surface of a fuselage or a wing of an aircraft. The honeycomb core sandwich panel is configured by sandwiching a honeycomb structured core with a plurality of cells having a hexagonal cross section are formed between a pair of outer skins.
In the honeycomb core sandwich panel used as the outer panel, a damaged portion may be formed reaching the core through the outer skin by a lightning strike or a flying object such as hail.
As a repair method employed when the damaged portion reaches the core, a repair space is formed by removing a position where the damaged portion is formed in the outer skin and the core, and the periphery thereof, and a honeycomb structured plug is inserted into the repair space and used as a substitute for the damaged core portion as described in, for example, ARP5089 COMPOSITE REPAIR NDT/NDI HANDBOOK, p. 87. The repair space is covered with a patch from above the plug, and the patch is bonded to the outer skin.
A pre-cured patch obtained by impregnating a fiber base material with thermosetting resin, and preliminarily curing the obtained object before repair can be used as the patch.
In accordance with the repair method according to ARP5089 COMPOSITE REPAIR NDT/NDI HANDBOOK, p. 87, the core is repaired by mounting the honeycomb structured plug, and the pre-cured patch as a substitute for the outer skin is supported by the plug. Thus, high rigidity equivalent to that before the panel is damaged is obtained.
However, it takes time to fabricate the honeycomb structured plug as a substitute for the core. A time required for the repair is thereby extended.
The panel may be repaired by using only the pre-cured patch without repairing the core. In this case, the pre-cured patch is not supported by the core. Thus, the rigidity is deteriorated as compared to that before the panel is damaged.
In view of the above problems, an object of the present invention is to quickly repair the honeycomb core sandwich panel while ensuring the rigidity of the honeycomb core sandwich panel.